阅读说明：本技术 功率模块钼搭桥连接方法 (molybdenum bridging connection method for power module ) 是由 曹剑龙 宗瑞 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种功率模块钼搭桥连接方法,涉及半导体模块连接结构方法技术领域,其包括DBC基板、设置于所述DBC基板上的第一芯片、钼桥、铅锡焊料、第二芯片和一端与第一芯片焊接另一端与第二芯片焊接的铜片。该功率模块钼搭桥连接方法,针对于传统工艺上,芯片本身热阻较大,综合性能指标下降,而新型工艺中,由于键合铝线过多,往往导致作业时间长,效率底,对生产设备有比较高的要求,前期投资成本高,本发明通过采用平面芯片,使用铅锡烧结,使得芯片与铜片之间能够简单快速的连接,同时利用钼桥进行过渡连接,实现各种方式的连接,这样使得加工作业简单,提高了工作效率,降低了生产成本。(The invention discloses a molybdenum bridging connection method for a power module, and relates to the technical field of semiconductor module connection structure methods. The molybdenum bridging connection method for the power module aims at the problems that in the traditional process, the thermal resistance of a chip is large, the comprehensive performance index is reduced, in the novel process, due to the fact that too many bonding aluminum wires exist, the operation time is long, the efficiency is low, high requirements are required for production equipment, and the early investment cost is high.)

1. The utility model provides a power module molybdenum bridging connection method, includes DBC base plate (1), set up first chip (2) on DBC base plate (1), molybdenum bridge (3), lead-tin solder (4), second chip (6) and one end and first chip (2) welding other end and second chip (6) welded copper sheet (5), its characterized in that: the two first chips (2) on the surface of the DBC substrate (1) are sintered at high temperature by utilizing lead and tin, copper sheets (5) with different sizes are used as connecting carriers, and transition connection is realized between one ends of the first chips (2) and the copper sheets (5) and between the other ends of the second chips (6) and the copper sheets (5) by utilizing molybdenum bridges (3), so that various connecting modes are realized.

2. The power module molybdenum bridge connection method according to claim 1, characterized in that: the molybdenum bridges (3) on the DBC substrate (1) are provided with bridges of different sizes according to the sizes of the first chip (2) and the second chip (6).

3. The power module molybdenum bridge connection method according to claim 1, characterized in that: and the appearance of the molybdenum bridge (3) is formed by installing a corresponding bridging die by using a 15T punch press in a metalworking workshop and shaping and processing the molybdenum plate into different appearance structures.

4. The power module molybdenum bridge connection method according to claim 1, characterized in that: the first chip (2) and the second chip (6) are both planar chips.

Technical Field

The invention relates to the technical field of semiconductor module connection structure methods, in particular to a molybdenum bridging connection method for a power module.

Background

In the production process of the semiconductor module, AK electrodes of a plurality of chips need to be physically connected to form various structural modes, the chips are made of monocrystalline silicon, lead and tin materials are generally used for physical connection through high-temperature welding, and stress action exists when the chips are connected with other metals during high-temperature welding, so that the chips are easy to lose efficacy. Therefore, at present, two ways are connected to the chip:

In the traditional process, a molybdenum sheet is combined on an AK electrode of a chip by some means, and the stress of the molybdenum sheet is close to that of monocrystalline silicon. The process has the advantages that the self thermal resistance of the chip is large, and the comprehensive performance index is reduced.

the novel process is to bond a plurality of aluminum wires on the surface of a planar chip (bare monocrystalline silicon), and the aluminum wires are uniformly distributed, so that no stress effect exists, and physical connection is realized. The process chip has excellent performance and is a mainstream connection mode in the market at present, but a plurality of aluminum wires are generally needed to be bonded on the surface of a single chip, the operation time is long, the efficiency is low, higher requirements on production equipment are needed, and the early investment cost is high, so that a molybdenum bridging connection method for the power module is needed, which can effectively avoid the stress action, can efficiently operate and connect and has lower requirements on the equipment.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a molybdenum bridging connection method for a power module, which solves the problems that in the traditional process, the chip self thermal resistance is large, the comprehensive performance index is reduced, and in the novel process, the operation time is long, the efficiency is low, the requirements on production equipment are high, and the early investment cost is high due to the fact that a plurality of bonding aluminum wires are excessive.

(II) technical scheme

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: a molybdenum bridging connection method for a power module comprises a DBC substrate, a first chip arranged on the DBC substrate, a molybdenum bridge, a lead-tin solder, a second chip and a copper sheet, wherein one end of the copper sheet is welded with the first chip, and the other end of the copper sheet is welded with the second chip: the two first chips on the surface of the DBC substrate are sintered at high temperature by utilizing lead and tin, copper sheets with different sizes are used as connecting carriers, and transition connection is realized between one ends of the first chips and the copper sheets and the other ends of the second chips and the copper sheets by utilizing molybdenum bridges, so that various connecting modes are realized.

Preferably, the molybdenum bridges on the DBC substrate are provided with different sizes of bridges according to sizes of the first chip and the second chip.

Preferably, the shape of the molybdenum bridge is formed by installing a corresponding bridging die by using a 15T punch press in a metalworking workshop, and shaping and processing the molybdenum plate into different shape structures.

Preferably, the first chip and the second chip are both planar chips.

(III) advantageous effects

The invention has the beneficial effects that:

1. The molybdenum bridging connection method for the power module aims at the problems that in the traditional process, the thermal resistance of a chip is large, the comprehensive performance index is reduced, in the novel process, due to the fact that too many bonding aluminum wires exist, the operation time is long, the efficiency is low, high requirements are required for production equipment, and the early investment cost is high.

2. According to the power module molybdenum bridging connection method, the shape of the molybdenum bridge is machined in advance, the working effect can be effectively improved, the trouble of machining diode module connection is reduced, and the power module molybdenum bridging connection method is compact in structure, reasonable in design and high in practicability. Not only can effectively avoid the stress action, but also can efficiently operate and connect a structural member with lower requirement on equipment.

Drawings

Fig. 1 is a schematic structural diagram of a molybdenum bridging connection method for a power module according to the present invention.

FIG. 2 is a diagram of a real object obtained by the method of the present invention.

In the figure: the chip comprises a 1DBC substrate, a 2 first chip, a 3 molybdenum bridge, a 4 lead-tin solder, a 5 copper sheet and a 6 second chip.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the present invention provides a technical solution: a molybdenum bridging connection method for a power module comprises a DBC substrate 1, a first chip 2 arranged on the DBC substrate 1, a molybdenum bridge 3, a lead-tin solder 4, a second chip 6 and a copper sheet 5, wherein one end of the copper sheet is welded with the first chip 2, and the other end of the copper sheet is welded with the second chip 6: the two first chips 2 on the surface of the DBC substrate 1 are sintered at high temperature by utilizing lead and tin, copper sheets 5 with different sizes are used as connecting carriers, and transition connection is realized between one ends of the first chips 2 and the copper sheets 5 and between the other ends of the second chips 6 and the copper sheets 5 by utilizing the molybdenum bridges 3, so that various connecting modes are realized. The physical representation is shown in FIG. 2.

The molybdenum bridges 3 on the DBC substrate 1 have different sizes of bridges according to the sizes of the first chip 2 and the second chip 6.

And the appearance of the molybdenum bridge 3 is formed by installing a corresponding bridging die by using a 15T punch press in a metalworking workshop and shaping and processing the molybdenum plate into different appearance structures.

The first chip 2 and the second chip 6 are both planar chips.

Aiming at the problems that in the traditional process, the chip has large thermal resistance and the comprehensive performance index is reduced, in the novel process, the operation time is long and the efficiency is low due to excessive bonding aluminum wires, the requirement on production equipment is high, and the early investment cost is high, the invention adopts the planar chip and uses lead-tin sintering to ensure that the chip and the copper sheet 5 can be simply and quickly connected, and meanwhile, the molybdenum bridge 3 is used for transitional connection to realize connection in various modes, so that the processing operation is simple, the working efficiency is improved, and the production cost is reduced.

The shape of the molybdenum bridge 3 is processed in advance, so that the working effect can be effectively improved, the trouble of processing the diode module for connection is reduced, and the device has the advantages of compact structure, reasonable design and strong practicability.

the operation steps of the invention take a diode module as an example:

The production process of the diode module is that a plurality of first chips 2 and a plurality of second chips 6 are sintered at high temperature through lead and tin, and a copper sheet 5 is used as a connecting carrier to realize various connecting modes; since the direct connection of the copper sheet 5 to the first chip 2 or the second chip 6 is liable to cause the electrical characteristics to fail, the molybdenum bridge 3 is required to be used for the intermediate transition connection. The diode module has various connection modes, and the sizes of the bridges provided according to the sizes of the first chip 2 or the second chip 6 are different.

Diode module test condition obtained by the process of the invention

Instruments used for the test: thyristor blocking characteristic tester, on-state and forward peak voltage test bench

And (4) qualified standard: IRRM less than or equal to 12mA VFM less than or equal to 2.00V

100 Amp diode Module parameter test data (test conditions IFM:300Atw:10ms)

Room temperature 25 degree parameters: inverse repeat peak voltage VRRM 400V

Inverse repetitive peak current IRRM ═ 0mA

Positive peak voltage VFM 1.57V-1.66V

High temperature 150 degree parameter: inverse repeat peak voltage VRRM 400V

Peak current IRRM ═ 0.2mA for inversion repetition

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.